To a certain extent you have automatic merge conflict resolution, that is what git merge
does. It just doesn't always work.
When two people change the same line in a file in different ways, git has no idea how to determine which change to do or how to combine the changes. So you need to provide it direction as to the correct state of the file. This really is a good thing.
You really don't want to have automatic merge resolution on all merges. Having this runs the risk of a merge being done incorrectly and your build being incredibly broken because of it. When you have conflicts, you want a set of human eyes looking at the changes and deciding what is the correct course of action.
Your actual problem is one of branching and management. You want to set up your branches and merges so minimize the number of conflicts that occur. Try to avoid having multiple people working in the same area at the same time. If that isn't possible, put them on the same branch so that they are sharing the code and getting each others changes regularly. Then have one person rebase and submit the change to gerrit and jenkins.